解
3x²y-[2xy-2(xy-3/2x²y)+xy]+3xy²
=3x²y-(2xy-2xy+3x²y+xy)+3xy²
=3x²y-(3x²y+xy)+3xy²
=(3x²y-3x²y)-xy+3xy²
=3xy²-xy
=xy(3y-1)
=3×(-1/3)[3×(-1/3)-1]
=-(-1-1)
=2
解
3x²y-[2xy-2(xy-3/2x²y)+xy]+3xy²
=3x²y-(2xy-2xy+3x²y+xy)+3xy²
=3x²y-(3x²y+xy)+3xy²
=(3x²y-3x²y)-xy+3xy²
=3xy²-xy
=xy(3y-1)
=3×(-1/3)[3×(-1/3)-1]
=-(-1-1)
=2